Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A reproducible and sensitive assay for melanotropic agents is described employing mouse melanoma cells in culture and measuring tyrosinase activity in terms of production of tritiated water from L-(ring-3,5-3H)-tyrosine. Molar concentrations of peptides inducing one-half maximal stimulation of tyrosinase activity were: beta-MSH, 1 +/- 2 x 10(-9); alpha-MSH and Beta h-LPH, 1 +/- 2 x 10(-8); ACTHp, 1 +/- 2 x 10(-7). Beta p 9-18-MSH and melanotropin potentiating factor, beta s 88-91-LPH exhibited no activity at concentrations as high as 10(-5)M.
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PMID:Assay of melanotropic peptides in an in vitro mammalian system. 679 95

Melanotrophin-potentiating factor (MPF) is a fragment of human beta-lipotrophin (LPH 88-91) which potentiates the action of alpha-MSH on Anolis skin. In the present study, we investigated the effect of MPF on MSH-induced melanogenesis. Pooled hair follicle scrapings from Siberian hamsters (Phodopus sungorus) were incubated for 48 hours with or without alpha-MSH and/or MPF. Melanogenesis was monitored by measuring tyrosinase activity and melanin accumulation. 10-8 M MPF potentiated the effect of no effect on melanogenesis, but 10-9 to 10-7 M alpha-MSH caused a dose-related increase. 10-8 M MPF potentiated the effect of each dose of alpha-MSH. Thus MPF potentiated MSH action on mammalian melanogenesis as well as on reptilian melanosome dispersion. Although each of these processes involve different intracellular responses the receptor mechanisms involved in each may therefore be the same.
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PMID:Melanotrophin-potentiating factor (MPF) potentiates MSH-induced melanogenesis in hair follicle melanocytes. 679 9